Personally if the pump is working and motorised valves are working ok and the system is full of sludge i would be checking for a blocked cold feed or partial blocked cold feed. If there is poor circulation this can certainly be responsible.
Circulation problem - and my plumber is desperate!
- Thread starter paulhodson
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Agile said:
But looking at the photos in my post - is that a problem?
Stop faffing about - get shot of the useless heating engineer - if he doesn't know sealed systems require a manufacturers fitted overheat stat on the boiler he's incompetent. Just because he works on commercial systems doesn't mean he's any good. (A friend of mine called me in yesterday to look at their large office block system, after a power cut nothing worked. The electircian spent an hour and a half getting nowhere. I just pressed the reset buttons on the timeclock - all working - yes some people are that useless.)
The whole airing cupboard is a lash up, cut out all the heating pipework starting at the 28mm flow in the corner. Re-configure to a standard H pattern. ie extend the flow pipe up into an H, the pump on the vertical leg coming back down and then split into the two zone valves. Stick the F&E tank up in the loft to raise the water head. The flow pipe side of the H carries on up to form the vent, the feed comes down into the other leg of the H. Use 22mm for the feed - less chance of blockage if your system is a bit sludged.
You can then check to see properly if there are any blockages. In particular check the pump impeller and zone valve blockage. The gate valves below the existing zone valves can also block. I suggest you change the ball/plate in zone valves (I assume they are Honeywell).
This may sound like a lot of work but it will allow easy maintainance of the pump/zone valves in the future.
If you can't even get the cylinder to heat up properly ie a simple pipe loop then theres no hope of the radiator circuit working.
The whole airing cupboard is a lash up, cut out all the heating pipework starting at the 28mm flow in the corner. Re-configure to a standard H pattern. ie extend the flow pipe up into an H, the pump on the vertical leg coming back down and then split into the two zone valves. Stick the F&E tank up in the loft to raise the water head. The flow pipe side of the H carries on up to form the vent, the feed comes down into the other leg of the H. Use 22mm for the feed - less chance of blockage if your system is a bit sludged.
You can then check to see properly if there are any blockages. In particular check the pump impeller and zone valve blockage. The gate valves below the existing zone valves can also block. I suggest you change the ball/plate in zone valves (I assume they are Honeywell).
This may sound like a lot of work but it will allow easy maintainance of the pump/zone valves in the future.
If you can't even get the cylinder to heat up properly ie a simple pipe loop then theres no hope of the radiator circuit working.
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Well – the follow up you were all waiting for! I am sorry this has turned into such a long thread – please don’t give up on me.
The plumber has spent the day here and has re-converted back to an open vented system with the F&E tank in the loft..
See pictures for the current view of the airing cupboard with the new cold feed and vent pipes disappearing through the ceiling and the old F&E tank removed.
and in the loft
Incidentally - the new plastic cold feed pipe is too hot to hold even at the point where it disappears into the roof space - is this to be expected?
As you may have guessed – the system has returned to the previous state where a few radiators upstairs are reasonably hot but those downstairs are totally cold! The return pipe under the hall floor is cold and the plumber says that the pump is trying to pump air not water. The flow side throughout the system is hot
So to summarise – the system works well when it converted to a sealed pressurised one – but our boiler is totally unsuitable for this.
When open vented – it does not work.
The fault therefore must lie in the pipe work (the layout – but it worked for the previous 20 years - or a blockage of sludge or air) Having said that, the time when it worked well was when it had the original venting arrangement (of a design I cannot remember) before an earlier plumber removed it to prevent it pumping over leaving it without a vent but still working OK
It would be a major job to replace even the return pipe, possibly involving destroying expensive (and very recently fitted) tiled floors, breaking into a boxed in enclosure surrounded by newly fitted bathroom cabinetry etc etc. . This has to be a last resort for me. I have mentioned in previous posts that I am due to sign a contract to sell the house soon – if this cannot be sorted out simply I will lose the sale
The fact it works when sealed but not otherwise would seem to imply that the blockage is air rather than sludge – so even with new pipe work of the same design the problem could be the same.
The only indication of any sludge is the strong magnetic attraction to the hot feed (28 mm reducing to 22mm) to the pump. I can find no other evidence – but then I cannot access most of the pipes.
www.paulhodson.f2s.com/magnetic.jpg
The plumber has suggested that fitting a new pressurised boiler might sort it out – which the previous experience of sealing the system would support – but it seems daft to change the only part of the system we know works! It would however, if successful be the simplest answer – at least in the short term. He is clearly not keen to do the work however – so it is not an attempt to make money out of me. (heaven only knows how much he is intending to charge for the work he has done so far which has left us with a worse outcome than when he came! I may however knock off the £150 cost of replacing the toilet seat cover which he has broken and not mentioned
).
Apart from technical advice – how can I find a competent heating engineer in the Stockport, Cheshire area of the country – any masochistic volunteers? Or is there any register I could refer to?
The plumber has spent the day here and has re-converted back to an open vented system with the F&E tank in the loft..
See pictures for the current view of the airing cupboard with the new cold feed and vent pipes disappearing through the ceiling and the old F&E tank removed.
and in the loft
Incidentally - the new plastic cold feed pipe is too hot to hold even at the point where it disappears into the roof space - is this to be expected?
As you may have guessed – the system has returned to the previous state where a few radiators upstairs are reasonably hot but those downstairs are totally cold! The return pipe under the hall floor is cold and the plumber says that the pump is trying to pump air not water. The flow side throughout the system is hot
So to summarise – the system works well when it converted to a sealed pressurised one – but our boiler is totally unsuitable for this.
When open vented – it does not work.
The fault therefore must lie in the pipe work (the layout – but it worked for the previous 20 years - or a blockage of sludge or air) Having said that, the time when it worked well was when it had the original venting arrangement (of a design I cannot remember) before an earlier plumber removed it to prevent it pumping over leaving it without a vent but still working OK
It would be a major job to replace even the return pipe, possibly involving destroying expensive (and very recently fitted) tiled floors, breaking into a boxed in enclosure surrounded by newly fitted bathroom cabinetry etc etc. . This has to be a last resort for me. I have mentioned in previous posts that I am due to sign a contract to sell the house soon – if this cannot be sorted out simply I will lose the sale
The fact it works when sealed but not otherwise would seem to imply that the blockage is air rather than sludge – so even with new pipe work of the same design the problem could be the same.
The only indication of any sludge is the strong magnetic attraction to the hot feed (28 mm reducing to 22mm) to the pump. I can find no other evidence – but then I cannot access most of the pipes.
www.paulhodson.f2s.com/magnetic.jpg
The plumber has suggested that fitting a new pressurised boiler might sort it out – which the previous experience of sealing the system would support – but it seems daft to change the only part of the system we know works! It would however, if successful be the simplest answer – at least in the short term. He is clearly not keen to do the work however – so it is not an attempt to make money out of me. (heaven only knows how much he is intending to charge for the work he has done so far which has left us with a worse outcome than when he came! I may however knock off the £150 cost of replacing the toilet seat cover which he has broken and not mentioned
).Apart from technical advice – how can I find a competent heating engineer in the Stockport, Cheshire area of the country – any masochistic volunteers? Or is there any register I could refer to?
H
holty
if i were you id report him to rouge traders for not knowing what a soldered joint looks like, and how a basic heating system works.also has he got shares in speedfit.
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holty said:
Is there a specific reason you mention that - apart from the minor point that the system doesn't work?
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JohnD said:
That would have been my (amateur) diagnosis as well - but why did it work 100% when he converted to sealed system?
And now the vent has been reintroduced to the system he says air is stopping the pump working as well - where is this coming from? (he says he hasn't a clue - and I wouldn't disagree with him!
Maybe I have two problems (not including the plumber)
H
holty
sludge is probably the biggest cause obviously because if a system is designed wrong it will sludge up.your plumber seems to ignore this, for the time hes spent he should of firstly arrange the vent feed pump arrangment then worked on from that, or his he just using the speedfit till he gets it right
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holty said:
Can you elaborate on that please?
H
holty
sorry got halfway down a page about trying to explain about negative and positive pressures and how heating systems should work, then deleted the lot. because it would take me to long to type . also as a paying customer its not your job to try and find out on this site how to solve your heating system for the plumber your paying. or is this a wind up
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holty said:
I give you my word this is not a wind up! Check the images - I have not got the time or energy to waste on such an elaborate and non- funny hoax!
I know it's not my job - but I am truly desperate. He has given up - other jobs to do and can't even come back for a month so any help on a sensible way forward (including how to find someone competent) would be gratefully received.
H
holty
i did check the images and to me every alteration is with speedfit wich can be reused by any amature. not saying you have done this but its hard to believe a plumber, or as you have said someone who is an industrial heating engineer,has not still been able to solve your problem seems unbalievable. i could turn up on your doorstep and tell you im with mi5 wolud you believe me. it sounds like youve been taken for a ride
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